The present invention relates to a liquid sealing type body mount provided between a body of a vehicle and a frame on a support side such as a suspension or the like in order to support the body in a vibration-proof manner.
Heretofore, a body mount used in a rear suspension of a vehicle such as an automobile has been known in which there are provided an inner cylinder coupled to one of a body of the vehicle and a suspension-side frame for supporting this body, and an outer cylinder coupled to the other of them, these inner and outer cylinders are joined to each other by a rubber elastomer provided between them, two liquid chambers, which are formed at portions opposed to each other with the aforesaid inner cylinder between, are provided between the inner and outer cylinders, and these liquid chambers are communicated with each other by an orifice passage to obtain a vibration damping effect by a liquid fluid effect between the two liquid chambers (for example, Japanese Patent Laid-Open Nos. 38730/1990 and 188832/1987).
In a case that the thus structured mount is used with the aforesaid liquid chambers positioned in the front and back directions of the vehicle, a stable vibration-proof characteristic can be obtained in some degree in upper and lower directions where a load of the body is applied due to an effect of a decrease of a moving spring constant.
However, in the front and back directions where the large vibration is applied at the accelerating time such as the starting time or at the braking time, rigidity becomes small due to a presence of the liquid chambers inside the rubber elastomer and displacement due to vibration grows larger, thus impairing the durability. Therefore, it is taken into account to provide a stopper which controls excessive displacement due to vibration in the direction orthogonal to the axis present in the liquid chambers. If the stopper is only made of rubber, sufficient rigidity will not be brought about during stopper action, thus there lies a problem of durability.
The present invention provides a liquid sealing type body mount the structure of which allows the stopper provided in the liquid chambers to function properly with high rigidity and also to improve the durability.
The invention relates to a liquid sealing type body mount provided between a body of a vehicle and a frame on a support side in order to support the body in a vibration-proof manner. The body mount comprises an inner cylinder fixed to one of the aforesaid body and a frame, an outer cylinder fixed to the other of them, a rubber elastomer that is provided between these inner and outer cylinders and elastically couples them to each other, two liquid chambers, which are formed at portions of this rubber elastomer opposed to each other with respect to the aforesaid inner cylinder and formed between the inner and outer cylinders, and an orifice passage for communicating these liquid chambers with each other. Further, in the body mount in which the load input of the body is performed in the axial direction, inside both the liquid chambers there is provided a stopper with a metal portion which protrudes from the inner cylinder in the radial direction embedded in a rubber portion formed integrally with the rubber elastomer, wherein the stopper has a slight gap between its loading end surface and a chamber wall surface on the liquid chamber outer circumference or is projectingly formed to the extent that it comes into contact with the chamber wall surface. It is preferable that the gap between the loading end surface of the stopper and the chamber wall surface is 1 mm or so or less than 1 mm.
According to the body mount, when the vibrating power orthogonal to the axial center acts in the opposite direction of the aforesaid both liquid chambers, the loading end surface of the stopper protruded from the inner cylinder in the liquid chambers comes into contact with the chamber wall surface or an inner surface of the outer cylinder on its opposite side so as to perform a stopper action, whereby capable of controlling large displacement of more than a predetermined one.
At this time, since the loading end surface of the stopper keeps a slight gap from the chamber wall surface or is formed projectingly to the extent of lightly coming into contact with the chamber wall surface and the outside is made of rubber, the loading end surface comes into contact elastically and loosely when the stopper acts, thus reducing its shock. Accordingly, an effect produced on passengers is small, providing better responsive effect. Furthermore, since the metal part protruded from the inner cylinder is embedded inside the rubber portion, its rigidity is higher than that of rubber only excessive deformation can be restrained on the outside rubber portion, thereby stopper action can be performed securely. Since the rubber portion can be restrained from being distorted, the durability will also be kept properly. Especially, since the metal part of the stopper is formed integrally with the inner cylinder, the durability is further improved.
It is preferable that a circumferential width of the aforesaid stopper, including the inside metal part, is formed large, thereby the durability can be improved.
Provided that the loading end surface of the stopper is chamfered on both circumferential sides and its corner portion is also rounded, abutment on the chamber wall surface on the outer circumferential side of the liquid chamber will be loosened.